Spray gun



J, C. HULL SPRAY GUN Aug. 8, 1933.

Filed July l5 1930 b M A M -mmm Patented Aug. 8, 1933 UNITED STATESPATENT OFFICE SPRAY GUN Application July 15, 1930. serial No. 468,189

1 Claim.

My invention relates to spray guns and more particularly has referenceto an improved valve construction for spraying devices and itscombination with the head of a spray gun. It is an object of the presentinvention to provide a valve structure for spray devices which enablesthe graduation of a narrow long spray to any desired degree of width andwhich possesses maximum projective spraying power.

Another object of my invention resides in the provision of a spray gunwhich includes but a single moving part in the head or spray endthereof, the said moving part being simple in operation and inexpensivein construction.

Spray guns of present design are usually constructed of elements whichrequire a high degree of precision thereby rendering the devices costlyin manufacture. It is therefore still another object of the invention toprovide a spray gun which is characterized by its simplicity and freedomfrom complicated parts.

Other objects and advantages of my invention will appear from the moredetailed description thereof.

Briefly stated, my improved construction comprises a hollow open-endtube, or valve-retaining member, having a plate or external flange atone end thereof, the plate preferably having angular openings in the rimthereof. Within the tube and adapted for sliding movement therein ismounted a control and shut-off valve which, according to a specificembodiment of this invention, comprises an enlarged body portion ofsquare cross section and a valve plug adapted for insertion through andwithdrawal from a central aperture in the plate or front end of thetube, this aperture preferably being of lesser diameter than theinternal diameter of the tube. This structure is adapted for assemblyinto a spray head of suitable construction, such as that shown in myprior Patents 1,221,861 granted April 10, 1917, and 1,561,646 grantedNovember 17, 1925, and which includes a centrally apertured cap threadedonto the head and a disc, having a spray orice therein, which is held inposition by the cap.

For a fuller understanding of my invention, reference will be had to theaccompanying drawing illustrating a preferred construction but it is tobe understood that the invention is not limited to the specic showing asvarious changes and modifications may be made therein without departingfrom the spirit and scope of the inven-r r tion as defined in theappended claims. In the D drawing,

Fig. 1 is a longitudinal sectional View of a spray gun embodying thefeatures of my invention;

Fig. 2 is a view of the valve-retaining member or sleeve and itsassociated whirl plate; and

Fig. 3 is a side view of Fig. 2.

Referring more particularly to the drawing, numeral 1 represents aconducting tube or barrel having screw threaded engagement at one endthereof with coupling 2, provided with inlet 3 which is threaded as at 4for the reception of a 65 hose connection. A valve rod or shaft 5 isdisposed centrally of the conducting tube and coupling, the latterhaving packing gland 6 and nut 7 for the shaft. The valve rod or shaftis provided with a screw or coarse thread 8, engaging a correspondinghelical recess within coupling 2, whereby the shaft may be movedlongitudinally of the barrel with but a turn of the wrist, the outer endof the shaft having an enlarged actuating member 9 or handle forimparting rotation 75 to the shaft by the operator.

Screw threaded to the opposite or spray end of conducting tube 1, asshown, is a spray head or nozzle body 10 having a pressure chamber 11formed therein. The outer end of the spray head is threaded to receive anozzle cap 12v having circular flange 13. A nozzle disc 14, havingcentral spray orice 15, and a gasket or washer 16 are disposed withincap 12 so that, when the latter is threaded into place on spray head 10,the gasket 16 is bound against the end of the spray head and disc 14 isbound between the gasket and flange 13 of the cap.

As a feature of the present invention, the outer end of spray head 10 isbored, as shown, to re- 90 ceive a whirl plate 17 or external ange ofthe valve-retaining member hereinafter described, the outer rim of whichplate or flange is milled to provide feed apertures 18. The plate formsan eddy chamber 19 with disc 14, the plate being 95 flush with the outerend of the spray head. The feed apertures are preferably four in numberand equally spaced circumferentially of the plate and are cut at anangle to the plate, as best shown in Fig. 3, in order to impart aswirling motion to the material passed therethrough.

A hollow cylindrical tube or sleeve extension 20 constitutes thevalve-retaining member and extends backwardly from plate 17 into thehead of the gun as shown, the tube and plate preferably being integral.Plate 17 is centrally apertured to provide a circular opening 21. Thediameter of this opening is uniform to but a short distance from theface of the plate and increases in the direction of the interior ofsleeve 20, as

shown, to form an internal flange 21'. In a preferred construction, thediameter of aperture 21 across the face of plate 17 is about one-halfinch and this diameter extends not more than onesixteenth inch into theplate. The diameter of aperture 21 then increases to merge, as shown,with the interior of sleeve 20 which is preferably bored toeleven-sixteenth inch. That is, the smallest thickness of flange 21 isnot more than one-sixteenth inch which gradually increases to abouteleven-sixteenth inch in the direction of the tube.

The tube or sleeve extension 20 of the whirl plate is adapted toslidably retain the control and shut-off valve which comprises the valvebody 22 substantially square in cross section and the integralcylindrical valve plug 23. When the sleeve 20 is bored toeleven-sixteenth inch as above stated, valve body 22 is preferably aboutone-half inch square in cross section while Valve plug 23 is lathed tofit the small diameter of aperture 21, its end being slightly tapered asshown. The outer end of plug 23 is provided with a resilient tip 24 ofrubber or the like which is adapted to seat against orice 15 to eiect ashutoff, the valve plug being of sufficient length to permit this whenthe control valve is moved outwardly toward disc 14. Valve body 22 isbored to receive the end of valve rod or shaft 5 and is rigidly heldthereon by means of cross pin 25.

In operation, the solution or mixture to be sprayed is supplied underpressure to the gun through inlet 3 and passes into pressure chamber 11andrinto the spaces between the flat sides of valve body 22 and theinterior of sleeve r2O. By moving the control valve backward and forwardby rotation of shaft 5, the aperture 21 may be opened and closed atwill, thus optionally effecting any desired degree of central dischargethrough the head of the gun for the purpose of greater projective powerof spray and making it possible to graduate a narrow long spray to anydesired width. When the control valve is moved forward so that plug 23is positioned in opening 21 but short of disc 14 as shown in Fig. 1, the

flow through the opening 21 is shut off and all the material issues in awhirling motion from pressure chamber 11 through feed apertures 18 intoeddy chamber 19 and thence through orifice 15. VWhen the valve is movedbackwardly of the gun so that plug 23 is withdrawn from aperture 21,part of the materialv discharges through feeder apertures 18 and partthrough central opening 21 into eddy chamber 19 thereby effectingcentral discharge of a portion of the material and furnishing greaterprojective spraying power. In the movement of the control valvelongitudinally of sleeve 20, it will be noted that the square corners ofbody portion 22 serve as a guide for the valve. In order to shut off thespray, the valve is moved outwardly to abut against disc 14 and closeoff orifice 15 by means of the resilient tip 24 on the valve plug.

From the foregoing it will be seen that I have devised an improved valvestructure for spray guns for effecting a controlled central dischargeand which is characterized by its simplicity of construction and minimumof moving parts.

Having described my invention, I claim:

A spray guncomprising in combination a spray head, a anged nozzle capsecured to the head, a centrally apertured disc within the cap, a Whirlplate fixed in the head in spaced relationship with the disc and havingspaced tangential openings in the periphery thereof, a central circularopening in said plate in alignment with and of larger diameter than theaperture of said disc, a hollow cylindrical sleeve rigid with andextending from said plate, between the circular and tangential openingsthereof backwardly into the spray head and spaced from the Walls of thelatter, a control valve slidably disposed in said sleeve comprising anenlarged body portion having spaced guiding contact with the sleeve anda cylindrical plug adapted to fit said circular opening and ofsufficient length to reach from` said opening to said disc, means formoving said valve lengthwise of the sleeve, and means for supplyingliquid to said head.

' JOHN C. HULL.

